Web feeding mechanism for screen printing machines



H. F. WORM Jan. 13, 1953 WEB FEEDING MECHAISM FOR SCREEN PRINTINGMACHINES Filed Nov. 5, 1949 2 SHEETS-SHEET l MN g QM $N 2.

m v m IN VEN TOR.-

H. F. WORM Jan. '13, 1953 WEB FEEDING MECHAISM FOR SCREEN PRINTINGMACHINES 2 SHEETS SHEET 2 Filed Nov. 5, 1949 Summon- Patented Jan. 13,1953 WEB FEEDING MECHANISM FOR, SCREEN;

PRINTING MACHINES? Hugo Fritz Worm, .Uddevalla, Sweden, assignor to Aktiebolaget Teximpex, Uddevalla, S wede 13', a

cornora tion of Sweden 7 aims .1

The present invention. relates to. screen printe ac ines. of t e pe, whre a stenci i-of. c'ertein. length is placed on the, material to beprinted and thec-olonring' matter is transferred to the material,whereaf-tfilt the stencil is removed and the material is advanced adistance corresponding to the lengthof the stencil before thestencil isagain placed, on the. material, By such a. printing where themeterial,for v instance a textile web, is moved step-wise over a, printing.table, it is very important thetthev length of the successivemovementsofl the webis constant and equal to the length of the stencil;so, that the stencil, which isg'uidedinfixed guiding means,

will always be placed in correct position re1a-.

fl jtq the. a e d min ed a tern Dnebbject of the inventi-onis to.provide a deitie by m ans" 1 wh c =t n: ise-m nient or the web isautomaticall limited, to the correct length and, theinvention isessentially characterized in that; s roller for the feeding of the webis constructed, and arranged toub e driven through an overload couplingand the-t there is provided" a wheel connect-ed to saidi roller by meansof e disengeging clutch and preferably.

located on'the roll er sheit, the rotati'Qn Qf'sa id wheel in atleestone, direction corresponding to the feeding of the web, is limitedby a.fixed stop member cooperatin with a movable stopv member driven by saidwheel.

In the accompanying drawings there is shown an embodiment] of the;invention applied. to a textileprinting'machine. In the drewing -sFig. 1

is anaxial section through the device according to the inv entionfFig. zisesid View of thefde vice shownin Fig. Fig 3yi-s f a. section on; theline 3 of Fig. 1'; Fig, 4;is a section on the line,

df r i i 15 i dii .1. s'et e5m nt r l vationshowing theogoeration of theshiftingycollar.

In-thedrewings I indicetes e roller, which is driving 'an endless rubbeix web 7 2; ontwhich; the:

fabric "tofbe p linted; is preferably secured by meehis: oi an adhesivesouthat it cannot slide.

rela vely to the rnbberweb ,Whi,Q' intnrn does lslide on the roller I onaccount of the friction qualities of the rubbern Theshaft 3iof the.

roller I projects outsid e;one oi its-bearings 4 and on the projecting.portion there is provided a chain wheel 5 for a driving chain from anelectric motor (not-shown); The;chein wheel 5 is rotetably mounted onthehub 6 of a, disk I secured to-the shaft- 3; To thehnbfi' issecuredanother disk 8 on the opposite side of the chain wheel 5 and..betweenthe disks mea s and the sides of. the chain wheel 5 there are providedfriction lrings 9, for inste nc frong fibrous material}. whichlring'sere pressed against the "wheel 5JsoY1that 'atthturning of the wheel a.limited torsionallimoment is transmitted the shaitidg Q 1 ee-" t 3 i fiss r urth otete y 22 mounted a, cos-wheel; I I): which can bercIiLtQ d othe'shaft w l b escr bed"belowi-andgwmc cooperates with a, toothe d 1rec k l,l slidin 1115 guide members I2.'; l 3.. The rack-ll'li'isgfittgitsone end provided with, a, stop ring- It! cooperatin withthe guide-member I'Z f or1ilni-ting the;-move-- ment of the rackin onedirection; Onythe-ra lc I I there is further fasteneda. stopimemberl5-in the shape. of a ring whichv cooperatesl withta race Is -on thefixedl lide member IL3E. Theistop; member, I 5 is displaceable', elongthehrackf and; can be secured to, itin; difierentfpositions by meansofa, screw I]; onthe rackctheretis ls'o; provided akscale I8 ionindicatingthedi s' lac ment position of the I stop, member I5; In-orderto avoid play betwefinfgthe reck, I lendfthelcog; wheel I 0 there isprovided atithe;backer theym'ck a diagrammatically,shownyroller l9'whichib'y sp in 91s ss d; aea nsttthelrarck, I I1 and-uni turnforcesthe racklageinstithe wheel Ill.

The cog w-heel'l I) can be coupled vto theshdfflf' by means of acoupling disk 2'I securedtojthic: shaft andpro-videdwithfanexielflanges-22. In" the cylind cal ringvfo medy,-said.flense sinih serted a cylin calip oiectinen rtionl inf-the;

" Wheel 9 e ea mallend emet rjthan the inft ner-diameter of the fiengefl; Intheringshapedl a e we e an e. andthewheeli o bnz r e ehsfidplitfing Mewhibl'! cam e e d, y meanseterotflahle camz pintz 5; tw e hends fm hfi ingand".W i hispfi Y6Ji' r WSST EC TQIL So thatlth l Hilin'-.'a. ,cer:- a l ng.- ce tin ;permit hesinsw en s he hz -erndgin anth r-inositio Hates t e rin en:ds.,. o.:th;et theri iiie xpended-ii Thepin 251is providedwitlra 'cylindricaltpQrtioh" 26; which is journeled;in; an 'atperturegin' thief; wheel I@. Outsidethiseperturejthecpinnortiont; is securedto a. 1ever"2-"l"bygmeansgofwhichthe pin 25 can be rotated. The swinging of theglever 21 is effectedby meens ofe conical f-ace 23fon11a; f collar 29 i lace bl nii' ei l nated hub of the wheel lflgwhi hjfaice" 2 8'coopera1z'es with the fre eend,of thejever; 21;,

s h wn in. the drawing helhift' etcolliar.19; is provided with atcircnlareroove 3l0j f0r en age? ment withflawclutch lever- 30f by rneensoiwhich; the shi ti ec la fl canv 'e movedaxiellvg Said; lever may, ifjdes i red,,. be connected togthe. start ing means .of the driving motorfontheirollelt so that the motor is started when": theefzrictione clutch-2 2...2.t is [thrown in; rand stop};edwhen -thfl tightened; the wheel l0, is disconnecte'dsfrqnro the shaft 3 andthe driving motor is at astandstill. At the same time the rack I l is in its lower position wherethe stop ring l4 abuts against the guide member 12. When the fabric hasto be advanced the motor is started and the clutch between the wheel l6and the shaft 3 is thrown in. On account of the brake 3|, 32, however,the shaft 3 is still standing still and the chain wheel 5 is rotatingbetween the disks 7 and 8. When i the brake is released the shaft 3begins to rotate and the rack ll is raised until the stop member 15abuts against the face 16 on the guide member l3 when the rotation ofthe shaft is stopped while the chain wheel still rotates. brake 3 l, 32has been tightened the motor can be stopped and the wheel l disconnectedfrom the shaft 3, whereby the rack H sinks down to the initial positionshown in the drawing.

It is evident that the maximum friction torque between the chain wheeland the shaft 3 must be smaller than the maximum friction torque between the flange 22 and the wheel Hi.

What I claim is:

1. A feeding mechanism for screen printing machines comprising a feedingroller for the material to be printed, a positively driven wheel, adriving connection comprising an overload coupling between saidpositively driven wheel and said roller, a rotatable wheel, a drivingconnection comprising a disengageable clutch between said roller andsaid rotatable wheel, a fixed stop member, .a, movable stop memberdriven by said rotatable wheel and cooperating with said fixed stopmember in order to limit the rotation of said rotatable wheel in atleast the direction corresponding to the feeding movement of the feedingroller. i

2. A feeding mechanism for screen printing machines comprising a feedingroller for the material to be printed, a positively driven wheel, adriving connection comprising an overload coupling between saidpositively driven Wheel and said roller, a rotatable wheel, a drivingconnection' including a disengageable clutch between said roller andsaid rotatable wheel, a fixed stop member, a movable stop member drivenby said rotatable wheel and cooperating with said fixed stop member inorder to limit the rotation of said rotatable wheel in at least thedirection corresponding to the feeding movement of the feeding roller,at least one of said stop members being adjustable to diiferentpositions for varying the feeding length of the materiah 3. A feedingmechanism for screen printing machines comprising a feeding roller forthe material to be printed, a positively driven wheel, a drivingconnection comprising an overload coupling between said positivelydriven wheel and said roller, a braking means for the roller locatedbetween said overload coupling and said roller, a rotatable wheel, adriving connection comprising a disengageable clutch between said rollerand said rotatable wheel, a fixed stop member and a movable stop memberdriven by said rotatable wheel and cooperating with said fixed stopmember in order to limit the rotation of said rotatable wheel in atleast the direction corresponding to the feeding movement of the feedingroller.

4. A feeding mechanism for screen printing machines comprising a feedingroller for the material to be printed, a positively driven wheel, adriving connection comprising an overload coupling between saidpositively driven wheel and said roller, a rotatable cogwheel, a movablerack cooperating with said cogwheel, a driving con- After the nectioncomprising a disengageable clutch between said roller and said rotatablecogwheel, a fixed stop member, a stop member secured to said movablerack and cooperating with said fixed stop member in order to limit therotation of said rotatable cogwheel in at least the directioncorresponding to the feeding movement of the feedin roller.

5. A feeding mechanism for screen printing machines comprising a feedingroller for the material to be printed, a positively driven wheel, adriving connection comprising an overload coupling between saidpositively driven wheel and said roller, a rotatable wheel, a drivingconnection comprising a disengageable clutch between said roller andsaid rotatable wheel, a fixed stop member and a movable stop memberdriven by said rotatable wheel and cooperating with said fixed stopmember in order to limit the rotation of said rotatable wheel in atleast the direction corresponding to the feeding movement of the feedingroller, said movable stop member automatically returning to its initialposition when the rotatable wheel is disconnected from the roller.

6. A feeding mechanism for screen printing machines comprising a feedingroller for the material to be printed, a positively driven wheel, adriving connection comprising an overload coupling between saidpositively driven wheel and said roller, a rotatable wheel, a drivingconnection comprising a disengageable clutch between said roller andsaid rotatable wheel, a fixed stop member, a movable stop member drivenby said rotatable wheel and cooperating with said fixed stop member inorder to limit the rotation of said rotatable wheel in at least thedirection corresponding to the feeding movement of the feeding roller,said overload coupling consisting of an overload friction clutch themaximum torque of which is such that it slips when the stop members comeinto contact with each other.

7. A feeding mechanism for screen printing machines comprising a feedingroller for the material to be printed, a positively driven wheel, adriving connection comprising an overload coupling between saidpositively driven wheel and said roller, a rotatable wheel, a drivingconnection comprising a disengageable clutch between said roller andsaid rotatable wheel, a fixed stop member, a movable stop member drivenby said rotatable wheel and cooperating with said fixed stop member inorder to limit the rotation of said rotatable wheel in at least thedirection corresponding to the feeding movement of the feeding roller,said overload coupling consisting of an overload friction clutch themaximum torque of which is such that it slips when the stop members comeinto contact with each other and said disengageable clutch consisting ofa friction clutch having a greater maximum torque than said overloadfriction clutch.

HUGO FRITZ WORM.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 530,385 Boatwright Dec. 4, 18941,110,328 Malm Sept. 15, 1914 1,222,957 Kramer Apr. 17, 1917 1,337,837Gore Apr. 20, 1920 2,291,668 Weigolt Aug. 4, 1942

